Method for treating eye disease or conditions affecting the posterior segment of the eye

ABSTRACT

This invention relates to the use of prodrug for the manufacture of a medicament useful for treating an ocular disease affecting the posterior segment of the eye, in a subject in need thereof, wherein the prodrug is a composition injected into the vitreous body, and the frequency of injections does not exceed one injection per month.

The present invention involves the fields of ophthalmology, more precisely the treatment of eye disease or conditions, especially disease or condition affecting the posterior segment of the eye.

The present invention relates to a method for in-vivo sustained release of an active agent through intraocular invasive delivery of a prodrug thereof.

Treatment of diseases or conditions affecting the posterior segment of the eye are complicated by the inaccessibility of the posterior eye to topically applied medications.

Treatments of posterior eye diseases require intravitreal or periocular injections or systemic drug administration. Local injections are usually preferred to systemic drug administration because the blood/retinal barrier impedes the passage of most drugs from the systemically circulating blood to the interior of the eye. Therefore large systemic doses are needed to treat eye posterior diseases, which often result in systemic toxicities.

There are diseases for which periocular injections do not allow the delivery of efficacious amounts to the target sites. For these diseases, intravitreal injections are found necessary. However, the short half-life of most injected compounds in the vitreous, a few hours only, requires frequent administrations.

Repeated intravitreal injections are responsible of side effects such as retinal detachment or cataract. Moreover, these injections are poorly accepted by patients unable to deal with the pain and discomfort.

Some research on implant devices has been conducted in order to address this technical problem. For example, US20050244469 discloses a method for treating an ocular condition comprising the insertion of an implant into an ocular site of a patient with an ocular condition, more preferably in the vitreous body of the eye of a patient to treat a condition or disease of the posterior segment of the eye.

However, there is a need for alternative solutions for providing therapeutic treatment of an ocular condition, such as posterior ocular condition. In particular, there is still a need for treatment over an extended duration, for example, time periods extending up to 30 days, 60 days, 90 days, 120 days, 6 months, 8 months, 12 months or more. There is also a need to reduce the frequency of injections, such that the number of injection should be equal or less than once a month, preferably equal or less than once every 2 months, more preferably equal or less than once every three months, most preferably equal or less than once every four, five or six months.

A recognized advantage of providing a method for an extended treatment is to prevent recurrence of the inflammatory or other posterior ocular condition treated. It can also minimize the number of surgical interventions required by the patient over time to treat an ocular condition.

It is a goal of this invention to provide a sustained release of a therapeutically amount of an active agent for an extended duration as described hereabove, with a reduced amount of injections.

More precisely, the invention relates to the use of prodrug for the manufacture of a medicament or an ophthalmic composition useful for treating an ocular disease affecting the posterior segment of the eye, in a subject in need thereof, wherein the prodrug is a composition injected into the vitreous body, and the frequency of injections does not exceed one injection per month, preferably the frequency of injection is once every two months, more preferably once every six months or more.

The invention also relates to the use of a prodrug for providing extended duration of treatment of an ocular disease affecting the posterior segment of the eye, in a subject in need thereof, said use comprising administering an amount of a prodrug enabling the sustained release of a therapeutically amount of said drug for a duration of at least one month, preferably at least 2 month, more preferably at least six months.

According to an embodiment of the invention, no drug can be detected in the vitreous or the molar ratio of the prodrug to the drug, in the vitreous, two months after one single injection of said prodrug, is more than 60.

According to another embodiment of the invention, the molar ratio of the prodrug to the drug, in the retina, two months after one single injection of said prodrug, is less than 60.

According to an embodiment of the invention, the molar ratio of the prodrug to the drug, in the choroid, two months after one single injection of said prodrug, is less than 60.

In a most preferred embodiment, the molar ratio of the prodrug to the drug, in the vitreous, two months after one injection of said prodrug, is more than 60 and the molar ratio of the prodrug to the drug, in the retina and/or in the choroid, two months after one injection of said prodrug, is less than 60.

Advantageously, the prodrug is injected in the vitreous in an amount enabling the sustained release of a therapeutically amount of said drug for a duration of at least one month, preferably at least 2 months, more preferably at least 6 months.

According to an embodiment, the prodrug is injected with a frequency of one injection every two months. In this embodiment, the release of the prodrug and its transformation into the drug is such that a therapeutic amount of drug is present on the target site, for example retina or choroid, during two months, the prodrug being sustaineously released during this period of time.

According to another embodiment of the invention, the prodrug is injected with a frequency of one injection every six months.

Preferably, the prodrug is within a composition, wherein said prodrug is in combination with any suitable excipient or carrier for ophthalmic use. According to a first embodiment, the carrier is oily. Examples of suitable oily carrier are mineral oils such as silicone, paraffin or vegetal oils such as medium chain triglycerides, castor oil, olive oil, corn oil, palm oil or any other oil suitable for intraocular injection.

According to another embodiment, the carrier is an emulsion, preferably an oil-in-water emulsion, more preferably an anionic emulsion. In the embodiment where the carrier is an anionic emulsion, it is preferred that said emulsion comprises colloid particles having an oily core surrounded by interfacial film, the film comprising surface active agents, lipids or both, at least part or the surface active agents or lipids in the interfacial film having negatively charged polar groups, and the colloid particles have a negative zeta potential. Preferably, the prodrug is comprised within the emulsion in an amount of about 0.01% to about 10% w/w of the composition. According to an embodiment, the prodrug is comprised in the amount of about 0.5% to about 3% w/w of the composition. In a preferred embodiment, the prodrug is comprised in an amount of about 2% w/w of the composition. In another preferred embodiment of the present invention, the prodrug is comprised in an amount of about 1% w/w of the composition.

The Applicant performed a number of tests and noticed that the invention had the further advantage that he could not detect any release of drug in the plasma, which may mean that there is none or few passage of the drug released through the general system of the subject, and in any event, no related side effect is observed.

In the meaning of this invention, injecting in the vitreous body means performing an intravitreal injection.

According to the invention, the hydrolysis of the prodrug results in therapeutically amounts of drug at the targeted site of action, preferably at retina and/or choroid.

According to a preferred embodiment of the invention, the half-life of the prodrug in the target tissue is of at least 15 days, preferably of at least 30 days, preferably of at least 60 days, preferably of at least 6 months.

The present invention intends to propose solutions for treating various ophthalmic or ocular conditions and diseases. The present invention is especially designed for the treatment of posterior ocular conditions, which means any disease, ailment or condition which primarily affects or involves a posterior ocular site such as choroid or sclera (in a position posterior to a plane through the posterior wall of the lens capsule), vitreous, vitreous chamber, retina, optic nerve (including the optic disc), and blood vessels and nerves which vascularize or innervate a posterior ocular site. A posterior ocular condition can include a disease, ailment or condition. Examples of such conditions include without limitation Macular Disorders such as myopia, Non-Exudative Age Related Macular Degeneration (Dry), Exudative Age Related Macular Degeneration (Wet), Choroidal Neovascular Membranes (others than ARMD) and Cystoid Macular Edema; Inflammatory Disorders such as Uveitic Retinal Disease, Endophthalmitis, Toxoplasmic Retinochoroiditis, Systemic General Disorders Associated with Retinal Uveitis or Retinochoroidal Syndromes (Syphilis, Tuberculosis, Lyme Diseases, Chung Strauss Disease, LED, etc), Neuroretinitis, Optic Neuritis; Vascular Disorders such as Diabetic Retinopathy (all stages), Diabetic Macular Edema, Arterial Occlusion, Venous Occlusion; Heredo Retinal Dystrophies such as Stargardt's Disease, Fundus Flavimaculatus, other Heredomacular Dysropy; Trauma caused by Laser, photodynamic therapy, Photocoagulation, Hypoperfusion During Surgery; Macular Hole; Retinal Disease Associated with Tumors, Posterior Uveal Melanoma, Retinoblastoma and Choroidal Metastasis

As used herein, “effective amount,” and “sufficient amount” may be used interchangeably and refer to an amount of an ingredient which is sufficient to achieve an intended physiological effect. Thus, a “therapeutically effective amount” refers to a non-toxic, but sufficient amount of an active agent, to achieve therapeutic results in treating a condition for which the active agent is known to be effective. The determination of an effective amount is well within the ordinary skill in the art of pharmaceutical sciences and medicine, in that it may depend on various biological factors or individual variation and response to treatments.

As used herein, “subject” refers to a mammal that may benefit from the administration of a composition or method as recited herein. Most often, the subject will be a human but can be of any animals.

As used herein, “about” means approximately or nearly and in the context of a numerical value or range set forth herein means .+−.10% of the numerical value or range recited or claimed.

As used herein, “administration,” and “administering” refer to the manner in which a prodrug is presented to a subject.

As used herein, “invasive” refers to a form of administration that ruptures or punctures a biological membrane or structure with a mechanical means across which a prodrug is being delivered.

As used herein, “active agent” or “drug” may be used interchangeably to refer to an agent or substance that has measurable specified or selected physiologic activity when administered to a subject in a significant or effective amount. Examples of drugs useful in the present invention include without limitation: antivirals, chosen from the group comprising idoxuridine, trifluorothymidine, trifluorouridine, acyclovir, ganciclovir, cidofovir, interferon, DDI, AZT, foscamet, vidarabine, irbavirin; non-steroidal anti-inflammatories chosen from the group comprising amfenac, ketorolac, indomethacin, ibuprofen, diclofenac, flurbiprofen, piroxicam and other COX2 inhibitors; cytokines, interleukines and growth factors epidermal growth factor, fibroblast growth factor, pigment epithelium growth factor, platelet derived growth factor, transforming growth factor beta, ciliary neurotrophic growth factor, glial derived neurotrophic factor, NGF, EPO, PLGF, brain nerve growth factor (BNGF), vascular endothelial growth factor (VEGF) and monoclonal antibodies or proteins inhibiting the activity of such cytokines and growth factors; anti-inflammatories chosen from the group comprising alclometasone, amcinonide, amcinafel, amcinafide, beclamethasone, betamethasone, clobetasone, chloroprednisone, clocortelone, cortisol, C21-des-methylpropionyl-ciclesonide, cortodoxone, difluorosone, descinolone, desonide, defluprednate, dihydroxycortisone, desoximetasone, dexamethasone, deflazacort, diflorasone, dichlorisone, fluazacort, flucetonide, flucloronide, fludrotisone, fluorocortisone, flumethasone, flunisolide, fluocinonide, fluocinolone, flucortolone, fluperolone, fluprednisolone, fluroandrenolone, flurandrenolide, fluorametholone, fluticasone, hydrocortisone, hydrocortamate, loteprendol, medrysone, meprednisone, methylprednisone, methylprednisolone, mometasone, paramethasone, prednisolone, and triamcinolone, salts, derivatives, and a mixture thereof; antiangiogenic compounds such as anecortave, combretastatin, vascular endothelial growth factor (VEGF) inhibitors, squalamine, AdPEDF, VEGF-traps; immunological response modifiers chosen from the group comprising mycophenolic acid, muramyl dipeptide, cyclosporins, interferons, interleukin-2, cytokines, tacrolimus, tumor necrosis factor, pentostatin, thymopentin, transforming factor beta.sub.2, erythropoetin; antineogenesis proteins; antibodies (monoclonal or polyclonal) or antibodies fragments, oligoaptamers, aptamers and gene fragments (oligonucleotides, plasmids, ribozymes, small interference RNA (SiRNA), nucleic acid fragments, peptides).

According to an embodiment of the invention, the drug has an ophthalmic physiologic therapeutic activity, whereas the prodrug is inactive.

According to another embodiment of the invention the prodrug is a drug, or is prepared from a drug, which has or was grafted with functional groups such as haloformyl, hydroxyl, aldehyde, alkyl, alkenyl, alkynyl, carboxamide, primary amine, secondary amine, tertiary amine, quaternary ammonium ion, azo (Diimide), benzyl, carboxylate, carboxyl, cyanate, thiocyanate, ether, ester, halo, primary ketimine, secondary ketimine, primary aldimine, secondary aldimine, isocyanide, isocyanate, isothiocyanate, ketone, nitrile, nitro, nitroso, peroxy, phenyl, phosphino, phosphate, phosphono, phosphate, pyridyl, sulfonyl, sulfo, sulfinyl or sulfhydryl groups.

As used herein, “prodrug” refers to a drug precursors which following administration, release the drug in vivo via some chemical or physiological process. According to an embodiment of the invention, the prodrug is inactive. According to an embodiment of the invention the prodrug releases the drug by a biological reaction, such as enzymatic cleavage. The prodrug is a composition including the pro-active ingredient, eventually in combination with any suitable excipient, especially any excipient injectable in the vitreous body of the eye. The term composition should not be construed as an implantable device.

According to an embodiment of the invention, the enzyme involved in the transformation of the prodrug into the drug may be:

Oxidoreductases acting on the CH, CH₂, CH—OH, aldehyde, oxo, CH—CH, CH—NH₂, CH—NH, sulfur, phosphorus, arsenic or heme groups of donors; oxidoreductases acting on NADH or NADPH; oxidoreductases acting on nitrogenous compounds, diphenols and related substances or hydrogen as donors; oxygenases; oxidoreductases acting on peroxide or superoxide radicals as acceptors; oxidoreductases acting on the iron-sulfur proteins as donors;

Transferases transferring one carbon, alkyl, aryl, nitrogenous, aldehyde or ketone groups; transferases; acyltransferases; glycosyltransferases; transferases transferring phosphorus-, selenium- or sulfur-containing groups;

Lyases such as carbon-carbon, carbon-oxygen, carbon-nitrogen, carbon-sulfur, carbon-halide or phosphorus-oxygen lyases;

Isomerases such as racemases and epimerases; intramolecular oxidoreductases; intramolecular transferases or intramolecular lyases;

Ligases forming carbon-oxygen, carbon-sulfur, carbon-nitrogen, carbon-carbon, phosphoric ester or nitrogen-metal bonds.

Preferred enzymes are hydrolases which act on ester or ether bonds; hydrolases acting on carbon-nitrogen, carbon-carbon, halide, phosphorus-nitrogen, sulfur-nitrogen, carbon-phosphorus, sulfur-sulfur or carbon-sulfur bonds; glycosylases; peptidases; hydrolases acting on acid anhydrides.

Preferred prodrugs are esters of drugs, wherein the ester group is of formula —COOR, or ether of drugs wherein the ester group is of formula OR, wherein R is a long alkyl chain, preferably a C4-C16 alkyl chain, more preferably any suitable lipophilic chain.

As used herein, alkyl means straight chain saturated hydrocarbon or branched saturated hydrocarbon. Preferred alkyl groups are those comprising more than 4 carbon atoms, preferentially more than 8 atoms, more preferentially more than 12 atoms.

The invention is further illustrated by the following example, which should not be considered in any way as a limitation the scope of the protection.

EXAMPLE 1. Analytical Methods for Simultaneous Determination of Dexamethasone and Dexamethasone Palmitate in Ocular Tissues

A liquid chromatographic-mass spectrometric method for the simultaneous determination of dexamethasone and dexamethasone palmitate in ocular tissues was developed. Analytes and internal standard (roxithromycine) were extracted from the tissues using acetonitrile and separated by reverse phase liquid chromatography with a C8 column and a gradient mobile phase. The compounds were detected by mass spectrometric detection (atmospheric pressure ionization) with selected ion monitoring (SIM) (393.0 for dexamethasone and 631.5 for dexamethasone palmitate). The method was selective for both compounds and the limits of quantification were 32.7 ng/g of retina and 71.6 ng/g choroid. The unweighed linear model was applied.

2. Intraocular Pharmacokinetics of Dexamethasone Palmitate and Dexamethasone Following Intravitreal Administration Methods:

One single unilateral injection of a 0.8% (8 mg/ml) dexamethasone palmitate emulsion was administered intravitreally (100 μL) to rabbits. Animals were sacrificed at days 1, 7, 14, 21, 28 or 60 days (n=4/timepoint). Dexamethasone (D) and dexamethasone palmitate (DP) in tissues were determined. All concentrations are expressed in ng/g

Results:

Day 1 Day 7 Day 14 Day 28 Day 60 Mean sd Mean sd Mean sd Mean sd Mean sd Retina DP 106 74 93 38 136 19 146 109 55 37 (nmol/g) D 7 2 11 4 6 4 4 1 2 2 (nmol/g) DP/P 15.14 8.45 22.6 36.5 0.036 Choroid DP 191 69 103 77 22 11 143 61 52 22 (nmol/g) D 12 6 12 7 9 4 4.2 1 3 2 (nmol/g) DP/P 15.91 8.58 2.44 35.65 17.33 Aqueous DP ND ND ND ND ND ND ND ND 0 0 humor (nmol/g) D ND ND ND ND ND ND ND ND 0 1 (nmol/g) ND: Not determined.

Following IVT injection of a dose of 800 μg of prodrug, dexamethasone therapeutic levels of about 1000 ng/g were maintained for at least 2 months in the target tissues. Moreover, considerable amounts of the prodrug dexapalmitate remained in both retina and choroid, indicating an even more long-lasting release.

At the same time, the amounts of steroid in the vitreous and plasma were undetectable, suggesting fewer (if any) side effects in adjacent sites. This last fact was corroborated by IOP measurements, which were normal 2 months following the injection. 

1. A method for treating an ocular disease affecting the posterior segment of the eye, in a subject in need thereof, comprising administering to said subject an effective amount of prodrug wherein the prodrug is a composition injected into the vitreous body, and the frequency of injections does not exceed one injection per month.
 2. The method according to claim 1, wherein two months after one injection of said prodrug; the drug cannot be detected in the vitreous or the molar ratio of the prodrug to the drug, in the vitreous, is more than
 60. 3. The method according to claim 1, wherein the molar ratio of the prodrug to the drug, in the retina, two months after one injection of said prodrug, is less than
 60. 4. The method according to claim 1, wherein the molar ratio of the prodrug to the drug, in the choroid, two months after one injection of said prodrug, is less than
 60. 5. The method according to claim 1, wherein the prodrug is injected in the vitreous in an amount enabling the sustained release of a therapeutically amount of said drug for a duration of at least one month, preferably at least 2 months, more preferably at least 6 months.
 6. The method according to claim 1, wherein the prodrug is injected at most once every two months, more preferably at most once every six months.
 7. The method according to claim 1, wherein the half-life of the prodrug is of at least 15 days.
 8. The method according to claim 1, wherein the prodrug is dexamethasone palmitate.
 9. The method according to claim 1, wherein the prodrug is in combination with any suitable excipient or carrier suitable for ophthalmic use.
 10. The method according to claim 1 wherein the prodrug is within an oily carrier.
 11. The method according to claim 1 wherein the prodrug is within an emulsion.
 12. The method according to claim 1, wherein the prodrug releases at least one drug selected in the group comprising antivirals, chosen from the group comprising idoxuridine, trifluorothymidine, trifluorouridine, acyclovir, ganciclovir, cidofovir, interferon, DDI, AZT, foscamet, vidarabine, irbavirin; non-steroidal anti-inflammatories chosen from the group comprising amfenac, ketorolac, indomethacin, ibuprofen, diclofenac, flurbiprofen, piroxicam and other COX2 inhibitors; cytokines, interleukines and growth factors epidermal growth factor, fibroblast growth factor, pigment epithelium growth factor, platelet derived growth factor, transforming growth factor beta, ciliary neurotrophic growth factor, glial derived neurotrophic factor, NGF, EPO, PLGF, brain nerve growth factor (BNGF), vascular endothelial growth factor (VEGF) and monoclonal antibodies or proteins inhibiting the activity of such cytokines and growth factors; anti-inflammatories chosen from the group comprising alclometasone dipropionate, amcinonide, amcinafel, amcinafide, beclamethasone, betamethasone, betamethasone dipropionate, betamethasone valerate, clobetasone propionate, chloroprednisone, clocortelone, Cortisol, cortisone, cortodoxone, difluorosone diacetate, descinolone, desonide, defluprednate, dihydroxycortisone, desoximetasone, dexamethasone, deflazacort, diflorasone, diflorasone diacetate, dichlorisone, esters of betamethasone, fluazacort, flucetonide, flucloronide, fludrotisone, fluorocortisone, flumethasone, flunisolide, fluocinonide, fluocinolone, fluocinolone acetonide, flucortolone, fluperolone, fluprednisolone, fluroandrenolone acetonide, fluocinolone acetonide, flurandrenolide, fluorametholone, fluticasone propionate, hydrocortisone, hydrocortisone butyrate, hydrocortisone valerate, hydrocortamate, loteprendol, medrysone, meprednisone, methylprednisone, methylprednisolone, mometasone furoate, paramethasone, paramethasone acetate, prednisone, prednisolone, prednidone, triamcinolone acetonide, triamcinolone hexacatonide, and triamcinolone, salts, derivatives, and a mixture thereof; antiangiogenic compounds such as anecortave, combretastatin, vascular endothelial growth factor (VEGF) inhibitors, squalamine, AdPEDF, VEGF-traps; immunological response modifiers chosen from the group comprising muramyl dipeptide, cyclosporins, interferons, interleukin-2, cytokines, tacrolimus, tumor necrosis factor, pentostatin, thymopentin, transforming factor beta.sub.2, erythropoetin; antineogenesis proteins; antibodies (monoclonal or polyclonal) or antibodies fragments, oligoaptamers, aptamers and gene fragments such as oligonucleotides, plasmids, ribozymes, small interference RNA, (nucleic acid fragments, peptides.
 13. The method according to claim 1, wherein the treatment or prevention of a disorder affecting the posterior segment of the eye,comprises the treatment of any disease, ailment or condition which primarily affects or involves a posterior ocular site such as choroid or sclera, vitreous, vitreous chamber, retina, optic nerve, and blood vessels and nerves which vascularize or innervate a posterior ocular site.
 14. The method according to any one of claim 1, wherein the disorder is one or more of the following: Macular Disorders such as myopia, Non-Exudative Age Related Macular Degeneration, Exudative Age Related Macular Degeneration, Choroidal Neovascular Membranes and Cystoid Macular Edema; Inflammatory Disorders such as Uveitic Retinal Disease, Endophthalmitis, Toxoplasmic Retinochoroiditis, Systemic General Disorders Associated with Retinal Uveitis or Retinochoroidal Syndromes (Syphilis, Tuberculosis, Lyme Diseases, Chung Strauss Disease, LED, etc), Neuroretinitis, Optic Neuritis; Vascular Disorders such as Diabetic Retinopathy, Diabetic Macular Edema, Arterial Occlusion, Venous Occlusion; Heredo Retinal Dystrophies such as Stargardt's Disease, Fundus Flavimaculatus, other Heredomacular Dysropy; Trauma caused by Laser, photodynamic therapy, Photocoagulation, Hypoperfusion During Surgery; Macular Hole; Retinal Disease Associated with Tumors, Posterior Uveal Melanoma, Retinoblastoma and Choroidal Metastasis.
 15. A method to extend the duration of a treatment of a disease or a condition of the posterior segment of an eye, in a subject in need thereof, comprising administering to said subject an effective amount of a prodrug wherein said prodrug is injected into the vitreous body at most one a month. 